Set `.castShadow` of `boolean` and added tags

src/lights/AmbientLight.d.ts

@@ -22,8 +22,10 @@ export class AmbientLight extends Light {
 
 	/**
 	 * This light cannot be used to cast shadows as it does not have a direction.
+	 * @default false
+	 * @override
 	 */
-	castShadow: undefined;
+	castShadow: boolean;
 	readonly isAmbientLight: true;
 
 }